The government said Monday that it plans to order all airlines to make changes that will reduce the chance of fuel tank explosions like the one that destroyed a TWA Boeing 747 more than nine years ago.
The Federal Aviation Administration proposed a rule that would give airlines the option of meeting minimum standards for fuel flammability or eliminating the sources of sparks that can cause an explosion.
Since the TWA Flight 800 accident, the FAA has ordered at least 60 changes to eliminate possible sources of sparks, such as chafed wiring.
FAA and Boeing also have developed so-called "fuel tank inerting" systems that reduce the oxygen in fuel tanks, making an explosion much less likely. The new technology wouldn't be required on airplanes, but it would satisfy the proposed regulation.
"We're proposing to increase the level of aircraft safety by reducing the potentially explosive ingredient of flammable fuel vapors," FAA Administrator Marion Blakey said in a statement.
The FAA estimates it will cost $313 million to retrofit 3,200 large passenger jets over the next seven years.
Boeing spokesman Jim Proulx said the company will install the systems on new 747s and 737s in mid-2006. New 777s will be outfitted with the devices in 2007 and 767s in 2008.
Existing models of those planes, along with 757s and Airbus A320s and A330s, would be covered by the new rule.
Fuel tank explosions are rare, but they have resulted in 346 deaths since 1989, including the TWA accident.
All 230 people aboard that flight perished when the Boeing 747 crashed off the coast of Long Island, NY, on July 17, 1996, en route to Paris.
Federal safety regulators said a spark in the wiring ignited vapors in the Boeing 747's partly empty fuel tank. Air conditioning units underneath the fuel tanks are believed to have heated the vapors inside the tank - making them more vulnerable to explosion - during the plane's two-hour delay at New York's John F. Kennedy International Airport.
The public has 120 days to comment on the proposal, which does not cover cargo airplanes.